/**
 * Contains the logic for connecting the filters with the website.
 *
 * @param graph required for calling a refresh after a filter change
 * @returns {{}}
 */
module.exports = function ( graph ){
  
  var filterMenu = {},
    checkboxData = [],
    menuElement = d3.select("#m_filter"),
    menuControl = d3.select("#c_filter a"),
    nodeDegreeContainer = d3.select("#nodeDegreeFilteringOption"),
    graphDegreeLevel,
    defaultDegreeValue = 0,
    degreeSlider;
  
  filterMenu.setDefaultDegreeValue = function ( val ){
    defaultDegreeValue = val;
  };
  filterMenu.getDefaultDegreeValue = function (){
    return defaultDegreeValue;
  };
  
  filterMenu.getGraphObject = function (){
    return graph;
  };
  /** some getter function  **/
  filterMenu.getCheckBoxContainer = function (){
    return checkboxData;
  };
  
  filterMenu.getDegreeSliderValue = function (){
    return degreeSlider.property("value");
  };
  /**
   * Connects the website with graph filters.
   * @param datatypeFilter filter for all datatypes
   * @param objectPropertyFilter filter for all object properties
   * @param subclassFilter filter for all subclasses
   * @param disjointFilter filter for all disjoint with properties
   * @param setOperatorFilter filter for all set operators with properties
   * @param nodeDegreeFilter filters nodes by their degree
   */
  filterMenu.setup = function ( datatypeFilter, objectPropertyFilter, subclassFilter, disjointFilter, setOperatorFilter, nodeDegreeFilter ){
    // TODO: is this here really necessarry? << new menu visualization style?
    menuControl.on("mouseover", function (){
      var searchMenu = graph.options().searchMenu();
      searchMenu.hideSearchEntries();
    });
    menuControl.on("mouseleave", function (){
      filterMenu.highlightForDegreeSlider(false);
    });
    
    addFilterItem(datatypeFilter, "datatype", "Datatype properties", "#datatypeFilteringOption");
    addFilterItem(objectPropertyFilter, "objectProperty", "Object properties", "#objectPropertyFilteringOption");
    addFilterItem(subclassFilter, "subclass", "Solitary subclasses", "#subclassFilteringOption");
    addFilterItem(disjointFilter, "disjoint", "Class disjointness", "#disjointFilteringOption");
    addFilterItem(setOperatorFilter, "setoperator", "Set operators", "#setOperatorFilteringOption");
    
    addNodeDegreeFilter(nodeDegreeFilter, nodeDegreeContainer);
    addAnimationFinishedListener();
  };
  
  
  function addFilterItem( filter, identifier, pluralNameOfFilteredItems, selector ){
    var filterContainer,
      filterCheckbox;
    
    filterContainer = d3.select(selector)
      .append("div")
      .classed("checkboxContainer", true);
    
    filterCheckbox = filterContainer.append("input")
      .classed("filterCheckbox", true)
      .attr("id", identifier + "FilterCheckbox")
      .attr("type", "checkbox")
      .property("checked", filter.enabled());
    
    // Store for easier resetting
    checkboxData.push({ checkbox: filterCheckbox, defaultState: filter.enabled() });
    
    filterCheckbox.on("click", function ( silent ){
      // There might be no parameters passed because of a manual
      // invocation when resetting the filters
      var isEnabled = filterCheckbox.property("checked");
      filter.enabled(isEnabled);
      if ( silent !== true ) {
        // updating graph when silent is false or the parameter is not given.
        graph.update();
      }
    });
    
    filterContainer.append("label")
      .attr("for", identifier + "FilterCheckbox")
      .text(pluralNameOfFilteredItems);
  }
  
  function addNodeDegreeFilter( nodeDegreeFilter, container ){
    nodeDegreeFilter.setMaxDegreeSetter(function ( maxDegree ){
      degreeSlider.attr("max", maxDegree);
      setSliderValue(degreeSlider, Math.min(maxDegree, degreeSlider.property("value")));
    });
    
    nodeDegreeFilter.setDegreeGetter(function (){
      return degreeSlider.property("value");
    });
    
    nodeDegreeFilter.setDegreeSetter(function ( value ){
      setSliderValue(degreeSlider, value);
    });
    
    var sliderContainer,
      sliderValueLabel;
    
    sliderContainer = container.append("div")
      .classed("distanceSliderContainer", true);
    
    degreeSlider = sliderContainer.append("input")
      .attr("id", "nodeDegreeDistanceSlider")
      .attr("type", "range")
      .attr("min", 0)
      .attr("step", 1);
    
    sliderContainer.append("label")
      .classed("description", true)
      .attr("for", "nodeDegreeDistanceSlider")
      .text("Degree of collapsing");
    
    sliderValueLabel = sliderContainer.append("label")
      .classed("value", true)
      .attr("for", "nodeDegreeDistanceSlider")
      .text(0);
    
    
    degreeSlider.on("change", function ( silent ){
      if ( silent !== true ) {
        graph.update();
        graphDegreeLevel = degreeSlider.property("value");
      }
    });
    
    
    degreeSlider.on("input", function (){
      var degree = degreeSlider.property("value");
      sliderValueLabel.text(degree);
    });
    
    
    // adding wheel events
    degreeSlider.on("wheel", handleWheelEvent);
    degreeSlider.on("focusout", function (){
      if ( degreeSlider.property("value") !== graphDegreeLevel ) {
        graph.update();
      }
    });
  }
  
  function handleWheelEvent(){
    var wheelEvent = d3.event;
    
    var offset;
    if ( wheelEvent.deltaY < 0 ) offset = 1;
    if ( wheelEvent.deltaY > 0 ) offset = -1;
    var maxDeg = parseInt(degreeSlider.attr("max"));
    var oldVal = parseInt(degreeSlider.property("value"));
    var newSliderValue = oldVal + offset;
    if ( oldVal !== newSliderValue && (newSliderValue >= 0 && newSliderValue <= maxDeg) ) {
      // only update when they are different [reducing redundant updates]
      // set the new value and emit an update signal
      degreeSlider.property("value", newSliderValue);
      degreeSlider.on("input")();// <<-- sets the text value
      graph.update();
    }
    d3.event.preventDefault();
  }
  
  function setSliderValue( slider, value ){
    slider.property("value", value).on("input")();
  }
  
  /**
   * Resets the filters (and also filtered elements) to their default.
   */
  filterMenu.reset = function (){
    checkboxData.forEach(function ( checkboxData ){
      var checkbox = checkboxData.checkbox,
        enabledByDefault = checkboxData.defaultState,
        isChecked = checkbox.property("checked");
      
      if ( isChecked !== enabledByDefault ) {
        checkbox.property("checked", enabledByDefault);
        // Call onclick event handlers programmatically
        checkbox.on("click")();
      }
    });
    
    setSliderValue(degreeSlider, 0);
    degreeSlider.on("change")();
  };
  
  function addAnimationFinishedListener(){
    menuControl.node().addEventListener("animationend", function (){
      menuControl.classed("buttonPulse", false);
      menuControl.classed("filterMenuButtonHighlight", true);
      
    });
  }
  
  filterMenu.killButtonAnimation = function (){
    menuControl.classed("buttonPulse", false);
    menuControl.classed("filterMenuButtonHighlight", false);
  };
  
  
  filterMenu.highlightForDegreeSlider = function ( enable ){
    if ( !arguments.length ) {
      enable = true;
    }
    menuControl.classed("highlighted", enable);
    nodeDegreeContainer.classed("highlighted", enable);
    // pulse button handling
    if ( menuControl.classed("buttonPulse") === true && enable === true ) {
      menuControl.classed("buttonPulse", false);
      var timer = setTimeout(function (){
        menuControl.classed("buttonPulse", enable);
        clearTimeout(timer);
        // after the time is done, remove the pulse but stay highlighted
      }, 100);
    } else {
      menuControl.classed("buttonPulse", enable);
      menuControl.classed("filterMenuButtonHighlight", enable);
    }
  };
  
  
  /** importer functions **/
  // setting manually the values of the filter
  // no update of the gui settings, these are updated in updateSettings
  filterMenu.setCheckBoxValue = function ( id, checked ){
    for ( var i = 0; i < checkboxData.length; i++ ) {
      var cbdId = checkboxData[i].checkbox.attr("id");
      if ( cbdId === id ) {
        checkboxData[i].checkbox.property("checked", checked);
        break;
      }
    }
  };
  
  filterMenu.getCheckBoxValue = function ( id ){
    for ( var i = 0; i < checkboxData.length; i++ ) {
      var cbdId = checkboxData[i].checkbox.attr("id");
      if ( cbdId === id ) {
        return checkboxData[i].checkbox.property("checked");
        
      }
    }
  };
  // set the value of the slider
  filterMenu.setDegreeSliderValue = function ( val ){
    degreeSlider.property("value", val);
  };
  
  filterMenu.getDegreeSliderValue = function (){
    return degreeSlider.property("value");
  };
  
  // update the gui without invoking graph update (calling silent onclick function)
  filterMenu.updateSettings = function (){
    var silent = true;
    var sliderValue = degreeSlider.property("value");
    if ( sliderValue > 0 ) {
      filterMenu.highlightForDegreeSlider(true);
    } else {
      filterMenu.highlightForDegreeSlider(false);
    }
    checkboxData.forEach(function ( checkboxData ){
      var checkbox = checkboxData.checkbox;
      checkbox.on("click")(silent);
    });
    
    degreeSlider.on("input")();
    degreeSlider.on("change")();
    
  };
  
  return filterMenu;
};
